Synergistic effect of photo-thermal catalytic glycerol reforming hydrogen production over 2D Au/TiO2 nanoflakes

Constructing efficient photothermal catalysts and understanding their photothermal synergistic effects for solar-driven conversion of biomass derivatives towards clean energy carriers are essential in the development of renewable energy and waste disposal. In this study, Au nanoparticles loaded on TiO2 nanoflakes were synthesized as photothermal catalysts for bio-derived glycerol photothermal reforming hydrogen production. The results found that the generation of photogenerated carriers is a crucial process in the photothermal reforming of glycerol. In particular, the hot electrons excited by plasmonic Au nanoparticles did not participate in the hydrogen production reaction through neither direct nor indirect transfer. Instead, the hot carriers promoted the intermolecular collisions between reactants through thermalization. In addition, such generated local heat could reduce the semiconductor impedance and improve the migration efficiency of photogenerated carriers, resulting in an efficient conversion of gas phase intermediates. As obtained, photothermal enhanced reforming can improve hydrogen yield by 58%, while the hydrogen generated constant and the absorption equilibrium constant was calculated as 2.38 mmol∙g−1∙h−1 and 7.00 mL∙mmol−1.